We have previously demonstrated that mouse Rtl1 is one of the major genes responsible for the placental abnormalities characteristic of these two syndromes, and also that the severity of the phenotypes of Kagami-Ogata syndrome, such as a bell-shaped thorax and neonatal lethality associated with respiratory problems, is associated with the degree of overproduction of human RTL1 (Kagami et al., 2008). This evidence concerns the gene RTL1 and multiple congenital anomalies due to 14q32.2 maternally expressed gene defect.